Re: [RFC PATCH] mm: fork: Prevent a NULL deref by getting mm only if the refcount isn't 0

2021-03-10 Thread Eric W. Biederman
Filippo Sironi writes: > We've seen a number of crashes with the following signature: > > BUG: kernel NULL pointer dereference, address: > #PF: supervisor read access in kernel mode > #PF: error_code(0x) - not-present page > ... > Oops: [#1] SMP PTI >

Re: [RFC PATCH] mm: fork: Prevent a NULL deref by getting mm only if the refcount isn't 0

2021-03-10 Thread Jens Axboe
On 3/10/21 5:37 AM, Filippo Sironi wrote: > We've seen a number of crashes with the following signature: > > BUG: kernel NULL pointer dereference, address: > #PF: supervisor read access in kernel mode > #PF: error_code(0x) - not-present page > ... > Oops: 0

[RFC PATCH] mm: fork: Prevent a NULL deref by getting mm only if the refcount isn't 0

2021-03-10 Thread Filippo Sironi
We've seen a number of crashes with the following signature: BUG: kernel NULL pointer dereference, address: #PF: supervisor read access in kernel mode #PF: error_code(0x) - not-present page ... Oops: [#1] SMP PTI ... RIP: 0010:__rb_erase_color+